Cardiac arrhythmias are a leading cause of death in the United States. The key to treating cardiac arrhythmias is to locate the target (active) site. A number of Catheter locating systems are known in the art, as exemplified by the following U.S. Patents:
U.S. Pat. No. 6,050,267, issued Apr. 18, 2000 and U.S. Pat. No. 5,944,022, issued Aug. 31, 1999, both entitled “Catheter positioning system” of inventors Nardella, et al.
U.S. Pat. No. 5,983,126, issued Nov. 9, 1999 and entitled Catheter location system and method, and U.S. Pat. No. 5,697,377, issued Dec. 16, 1997 and entitled Catheter mapping system and method,” both of inventor Wittkampf.
U.S. Pat. No. 5,694,945 entitled “Apparatus and method for intrabody mapping;” U.S. Pat. No. 5,568,809 entitled “Apparatus and method for intrabody mapping;” U.S. Pat. No. 5,546,951 entitled “Method and apparatus for studying cardiac arrhythmias;” U.S. Pat. No. 5,480,422 entitled “Apparatus for treating cardiac arrhythmias;” U.S. Pat. No. 5,443,489 entitled “Apparatus and method for ablation;” U.S. Pat. No. 5,391,199 entitled “Apparatus and method for treating cardiac arrhythmias;” U.S. Pat. No. 5,713,946 entitled “Apparatus and method for intrabody mapping;” and U.S. Pat. No. 5,840,025 entitled “Apparatus and method for treating cardiac arrhythmias,” all of inventor Ben-Haim, alone or with others, and all assigned to Biosense, Inc. of New Brunswick, N.J.
U.S. Pat. No. 6,226,543 of inventors Gilboa, et al., issued May 1, 2001 and entitled “System and method of recording and displaying in context of an image a location of at least one point-of interest in a body during an intra-body medical procedure” and U.S. Pat. No. 6,188,355 of Gilboa, issued Feb. 13, 2001 for “Wireless six-degree-of-freedom locator.”
U.S. Pat. No. 6,216,027 of inventors Willis, et al., issued Apr. 10, 2001 and entitled “System for electrode localization using ultrasound” and U.S. Pat. No. 5,820,568 of inventor Willis, issued Oct. 13, 1998 for “Apparatus and method for aiding in the positioning of a catheter,” both assigned to Cardiac Pathways Corporation of Sunnyvale, Calif., and more generally referred to herein as the “Willis et al. patents.”
The Willis et al. patents describe the use of ultrasonic sensors mounted on a mapping catheter and on two other catheters to determine the position of the mapping catheter by triangulation. The mapping catheter can include one or more electrodes suitable for ablation. By using triangulation techniques, catheters can be navigated through a patient with minimal use of fluoroscopy.
Also known in the art are electrophysiology (EP Systems) for recording and analyzing electrogram signals received from multiple electrodes, for example, from a multielectrode mapping and ablation catheter. The EP Lab System available from C.R. Bard, Inc., Murray Hill, N.J., for example, is able to automatically measure activation times on multiple channels simultaneously. Activation times are typically calculated relative to a stable recording channel such as a surface ECG.
Historically, EP Systems have provided a variety of physiological information to the operator without a true association of the location of the operative catheter at which the physiological information was measured. The physiological information conventionally obtained from a roving catheter includes, among other data, intracardiac ECG signals, temperature, pressure, and impedance.
One early attempt to mate physiological information of a heart with the location of a catheter called for the placement of a sensor-laden sack positioned about the heart. The sensors on the sock provided a position verses physiological-condition map on a display with a full color interpolated image of activation time, temperature, and other physiologic parameters. Placing the sock around the heart, however, was an invasive procedure.
A relatively modem approach proposed by Ben-Haim et al. combines a portion of an EP system with a catheter positioning system and joins the physiologic data together with location information into a data point. Multiple data points are gathered as the operator repositions a singular mapping catheter and records physiologic data at new catheter positions. The data points from these separate measurements are displayed together to define a map, although the data points are collected over multiple heartbeats and are limited to a single mapping electrode pair. Data from the separate measurements are also analyzed and the regions between them are interpolated and included in the map. The resulting map provides a view of changes of the physiologic parameter under investigation (e.g. activation time) with position.
For many procedures it is important to advise the operator of the locations that have already been examined. However, when a great number of locations have been examined, the physiological data associated with each of these locations can obscure meaningful data when all of this information is displayed together in a composite map as in prior art approaches. There remains a need in the art for the selective display of only a portion of the physiologic data that has been gathered. There also remains a need for a system and method that permits selective and sequential playback of data points selected in accordance with prescribed criteria. There further remains a need for a system and method that can sequentially display changes in physiologic parameters at a given set of locations before and after a procedure (e.g. activation time before and after ablation). There also exists a need to gather and display multiple measurements from a single heartbeat to increase the speed and accuracy at which data can be gathered. The present invention addresses these and other needs.